Results of HARPS-N observations of the transiting system Qatar-1 in GAPS E. Covino M. Esposito, M. Barbieri, S. Desidera, L. Mancini, V. Nascimbeni, J. Southworth, A. Sozzetti, R.Claudi, K. Biazzo, N. Lanza, G. Piotto, & GAPS team GREAT-ESF Gaia and Exoplanets Workshop – Turin 5- 7/Nov/2012 T-ESF Gaia and Exoplanets
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Results of HARPS-N observations of the transiting system Qatar-1 in GAPS
Results of HARPS-N observations of the transiting system Qatar-1 in GAPS. E. Covino M. Esposito, M. Barbieri, S. Desidera, L. Mancini, V. Nascimbeni, J. Southworth, A. Sozzetti, R.Claudi, K. Biazzo, N. Lanza, G. Piotto, & GAPS team. - PowerPoint PPT Presentation
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Results of HARPS-N observations of the transiting system Qatar-1
in GAPS
E. Covino
M. Esposito, M. Barbieri, S. Desidera, L. Mancini, V. Nascimbeni, J. Southworth, A. Sozzetti, R.Claudi,
K. Biazzo, N. Lanza, G. Piotto, & GAPS team
GREAT-ESF Gaia and Exoplanets Workshop – Turin 5-7/Nov/2012 GREAT-ESF Gaia and Exoplanets Workshop
Gaudi & Winn (2007)
The shape of the RM anomalydepends on the trajectory of the transiting planet.
What can we learn from RM effect observations?
Why is the RM effect interesting?
• Type II migration: disk-planet interaction
small eccentricity and inclination
roughly explains semi-major axis distribution (Ida & Lin 2004)
• Kozai migration: perturbation by off-plane massive companion
possible large eccentricity and inclination
explain eccentricity distribution when combined with Type II migration models
is connected with the planet migration mechanism
Observational panorama
~60 systems with RM effect measured
Most planets are aligned (||<30º).
Misaligned planets seem more frequent around slightly more evolved stars or hotter than ~6000K (Winn et al. 2010), though still an open issue (Moutou et al. 2011).
Motivation of the GAPS RM effect subprogram
• derived via the RM effect is an important constraint on spin-orbit alignment and a basic parameter to characterize planetary orbits and test planet migration models
• Study tidal interaction with host star of close-in GPs
• Confirmation of transiting planet candidates
Study of RM effect for transiting planets provides clues on architecture and orbital evolution of
planetary systems
The GAPS RM-effect subprogram: targets
This sub-program of GAPS is aimed to determine/improve fundamental orbital parameters for transiting planets, i.e. derive the spin-orbit misalignement through observation of the Rossiter-McLaughlin (RM) effect
Selected Targets include stars with:
V<13, DEC>-30 and VsinI>1km/s
spanning a range of stellar and planet properties
Excluded objects with:
RM effect already measured
Kepler targets
HARPS-N observations of the transiting system Qatar-1
Hot Jupiter orbiting a (V~12.8mag) metal-rich K-dwarf star in about 2.4 days (Alsubai 2010)
• Obtained 11 spectra (exp-time=900s, S/N~30 at 6000Å, σ
RV~4.5m/s) covering transit on September 3:
RM effect successfully detected
• Out-of-transit data gathered in six following nights (Sep 5, 6, 7, 8, 9, 11):
new RVC solution
RVC from Alsubai (2010)
Observed R-M effect
Qatar-1 spectroscopic orbit
New orbital solution based on HARPS-N data consistent with a circular orbit
Adopted model as in Queloz et al. (2000), based on the following assumptions:average line profile as from CCF; stellar disc modelled by a 2000x2000 matrix,each element contributing with a Gaussian line profile (macroturbulence), characterized by a given velocity along the line-of-sight due to stellar rotation and limb-darkening coefficients (Claret 2004).Total profile resulting from convolution with HARPS-N instrumental profileThe model considers the actual area of the disc that is occulted during an exposureand the phase smearing due to the planet's displacement.
Qatar-1 RM effect model
Qatar-1 phase-smearing in RM effect
The model takes into account the actual area of the disc that is occulted during each (900s) exposure and the phase smearing due to the planet's displacement.Total transit duration ~1.62 hours
Qatar-1 phase-smearing in RM effect
The model takes into account the actual area of the disc that is occulted during each (900s) exposure and the phase smearing due to the planet's displacement.Total transit duration ~1.62 hours
Orbit Star Planet
P = 1.4200239 ± 0.0000010 days M* = 0.85 ± 0.03 M
SunM
pl = 1.33 ± 0.05 M
Jup
a = 0.0023 ± 0.0002 AU R* = 0.80 ± 0.12 R
SunR
pl = 1.21 ± 0.19 R
Jup
e = 0.020 ± 0.010 Teff
= 4820 ± 50 K ρpl
= 0.75 ± 0.42 ρJup
i = 83.82 ± 0.25 deg log(g) = 4.43 ± 0.10
b = 0.675 ± 0.016 [FeI/H] = 0.25 ± 0.10
K = 266 ± 4 m/s VsinI = 2.5 ± 0.5 km/s = 1.5 ± 0.6 km/s
T14
= 0.067491 ± 0.000018 days ξ = 0.90±0.05 km/s
TC
= 2455518.41131 ± 0.00039 BJD
±deg
Qatar-1 system properties
Qatar-1 system properties
New RVC solution consistent with a circular orbit
Orbit well aligned within uncertainties with star spin axis
Determination of star Teff, log g, [Fe/H], vsinI from
Estimated star Prot ~20 days yields agegyro of ~1.3 Gyr (for B-V=0.9, using Eq. 3 of Barnes 2007)
Porb much shorter than stellar Prot implies that tidal interaction is causing angular momentum to be tranferred from planet orbit to the star, and planet is going to be engulfed.
Conclusions
New RVC solution consistent with a circular orbit
Orbit aligned within the uncertainties with spin axis